Incoming and resident animals at NIEHS are monitored for morphological abnormalities, spontaneous diseases and parasitism. The health status of research animals is vital to reliable interpretation of experimental data. The incidence of respiratory disease is very low among laboratory rodents. Enteric pathogens have not been detected. Pinworm infections are moderately frequent but sporadic. No pathologic lesions can be attributed to these nematodes. The incidence of pasteurellosis in NZW rabbits has been greatly reduced since purchasing them from a new source. Infectious disease in guinea pigs or hamsters has not been encountered. BIBLIOGRAPHIC REFERENCES: Gupta, B.N.: Lymphosarcoma in a Rabbit. Am. J. Vet. Res. 37: 841-843, 1976. Cunliffe-Beamer, T.L. and Feldman, D.B.: Vaginal Septa in Mice: Incidence, Inheritance, and Effect on Reproductive Performance. Lab. Anim. Sci. 26: 895-898, 1976.